China built strategic petroleum reserves that can operate for over a year so that if the US attempted to blockade oil supplies from the middle east during a conflict, China could press on when they decide to obtain Taiwan (or so the geopolitical strategy thesis goes). Does it make sense to take Taiwan once China has their own semiconductor manufacturing capabilities and Taiwan is mostly a retirement home [1]? Hard to say. Old people in power take illogical and unconventional actions out of nostalgia, historically speaking.

[1] https://news.ycombinator.com/item?id=50260274